Toradex Colibri - Colibri Power Management Strategies; Colibri Power Supply and Signal Requirements

Colibri Carrier Board Design Guide
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3 Power Management
3.1 Power Supply Design
All Colibri modules can be powered with a single main power supply powering VCC,
AVDD_AUDIO, and VCC_BACKUP. If the Real-Time Clock (RTC) feature is required, a low current
backup power supply for the VCC_BACKUP is recommended. For better audio and ADC
performance, a separate low-noise supply for the AVDD_AUDIO is recommended. The main power
supply input can accept a voltage range between 3.135V and 3.465V (absolute). This allows
supplying the module from a 3.3V +/-5% power supply.
The Colibri form factor is specified for a maximum sustained power consumption of up to 10W and
a maximum peak power consumption of up to 15W for the SoMs.
The peak/maximum power consumption of individual SoMs depends on the use case, the silicon
revision of the SoC, the versions of software components being used, and the ambient
temperature, among other factors. For this reason, as a general rule of thumb, we recommend
scaling the carrier board power supplies for being able to reliably deliver the maximum peak
power consumption specified for Colibri modules in order to ensure compatibility with the broadest
range of existing and future Colibri modules.
Do not forget to take the additional power consumption of the carrier board peripheral devices on
the module power rail (3.3V) into the power budget. Most of the GPIO-capable I/O pins operate at
a 3.3V logic level.
3.2 Power Signals
3.2.1 Digital Supply Signals
Colibri
Pin
Colibri
Signal Name
I/O
Type
Power
Rail
Description
42, 84,108, 148,182,198, 200
VCC
I
PWR
3.3V
Main power supply input for the module
39, 41, 83, 109,147, 181, 197,
199
GND
I
PWR
Signal and power ground
40
VCC_BACKUP
I
PWR
3.3V
RTC supply, connect this pin to 3.3V even if
the internal RTC is not used
Table 25: Digital Supply Signals
3.2.2 Analog Supply Signals
Colibri
Pin
Colibri
Signal Name
I/O
Type
Power
Rail
Description
10, 12
AVDD_AUDIO
I
PWR
3.3V
Power supply for the analog part of the
module
9, 11
VSS_AUDIO
I
PWR
Ground for the analog part of the module
Table 26: Analog Supply Signals
The analog power supply is used on the module for the analog circuits. 3.3 Volt needs to be
provided to this input even if the analog part is not used in a design. In this case, the pins can be
connected to the main power input of the module. It is recommended for better audio quality to
add separate filters to the analog power supply rail. For the best quality, a separate power supply
with a linear voltage regulator is recommended.